09-11-2012, 12:17 PM
Artificial Neural Network
Artificial Neural.docx (Size: 666.33 KB / Downloads: 26)
The human brain contains about 100 billion nerve cells called neurons, each individually linked to other neurons by way of connectors called axons and dendrites. Signals at the junctures (synapses) of these connections are transmitted by the release and detection of chemicals known as neurotransmitters. The established neuroscientific consensus is that the human mind is largely an emergent property of the information processing of this neural network.
Importantly, neuroscientists have stated that important functions performed by the mind, such as learning, memory, and consciousness, are due to purely physical and electrochemical processes in the brain and are governed by applicable laws. For example,Christof Koch and Giulio Tononi wrote in IEEE Spectrum:
"Consciousness is part of the natural world. It depends, we believe, only on mathematics and logic and on the imperfectly known laws of physics, chemistry, and biology; it does not arise from some magical or otherworldly quality."[5]
The concept of mind uploading is based on this mechanistic view of the mind, and denies thevitalist view of human life and consciousness.
Eminent computer scientists and neuroscientists have predicted that computers will be capable of thought and even attain consciousness, including Koch and Tononi,[5] Douglas Hofstadter,[6] Jeff Hawkins,[6] Marvin Minsky,[7] Randal A. Koene,[8] and Rodolfo Llinas.[9]
Such a machine intelligence capability might provide a computational substrate necessary for uploading.
However, even though uploading is dependent upon such a general capability it is conceptually distinct from general forms of AI in that it results from dynamic reanimation of information derived from a specific human mind so that the mind retains a sense of historical identity (other forms are possible but would compromise or eliminate the life-extension feature generally associated with uploading). The transferred and reanimated information would become a form of artificial intelligence, sometimes called an infomorph or "noömorph."
Many theorists have presented models of the brain and have established a range of estimates of the amount of computing power needed for partial and complete simulations.[citation needed] Using these models, some have estimated that uploading may become possible within decades if trends such as Moore's Law continue.[10]
Immortality/backup
In theory, if the information and processes of the mind can be disassociated from the biological body, they are no longer tied to the individual limits and lifespan of that body. Furthermore, information within a brain could be partly or wholly copied or transferred to one or more other substrates (including digital storage or another brain), thereby reducing or eliminating mortality risk. This general proposal appears to have been first made in the biomedical literature in 1971 by biogerontologist George M. Martin of the University of Washington.[3]
Speedup
A computer-based intelligence such as an upload could potentially think much faster than a human even if it were no more intelligent. Human neurons exchange electrochemical signals with a maximum speed of about 150 meters per second, whereas the speed of lightis about 300 million meters per second, about two million times faster. Also, neurons can generate a maximum of about 200 to 1000action potentials or "spikes" per second, whereas the number of signals per second in modern[when?] computer chips is about 3GHz[citation needed] (about two million times greater) and expected to increase by at least a factor 100. Therefore, even if the computer components responsible for simulating a brain were not significantly smaller than a biological brain, and even if the temperature of these components was not significantly lower, Eliezer Yudkowsky of the Singularity Institute for Artificial Intelligence calculates a theoretical upper bound for the speed of a future artificial neural network. It could in theory run about 1 million times faster than a real brain, experiencing about a year of subjective time in only 31 seconds of real time.[11][12][13]
However, such a massively parallel implementation would require separate computational units for each of the hundred billion neurons and each of the hundred trillion synapses. That requires an enormously large computer or artificial neural network in comparison with today's super-computers.[12] In a less futuristic implementation, time-sharing would allow several neurons to be emulated sequentially by the same computational unit. Thus the size of the computer would be restricted, but the speedup would be lower. Assuming thatcortical minicolumns organized into hypercolumns are the computational units, mammal brains can be emulated by today's super computers, but with slower speed than in a biological brain.[14]
Space travel
Mind uploading poses potential benefits for interstellar space travel because it would allow immortal beings to travel the cosmos without suffering from extreme acceleration. A whole society of uploads can be emulated by a computer on a very small spaceship, that would consume much less energy than traditional space travels. The uploads would have control of the ship and would be able to make decisions about the crafts voyage in real time, independent of signals from Earth, that might eventually take months or years to reach the craft as it journeys out into the cosmos. Because a virtual conscious can be set into a state of hibernation, or slowed down, the virtual minds need not experience the boredom of hundreds if not thousands of years of travel. Instead they would only awake when on board computers detected that the craft had arrived at its destination. In the book Omega point, the author suggests that the universe eventually would be colonized by such machine intelligence.
Another possibility for travel would be to transmit a mind via laser, or via radio between two already inhabited locations. Such travel would require only the energy to transmit enough powerful signals so that they reach the target destination. The travelers experienced time from transmitter to receiver would be instantaneous.
Multiple/parallel existence
Another concept explored in science fiction is the idea of more than one running "copy" of a human mind existing at once. Such copies could potentially allow an "individual" to experience many things at once, and later integrate the experiences of all copies into a central mentality at some point in the future, effectively allowing a single sentient being to "be many places at once" and "do many things at once"; this concept has been explored in fiction. Such partial and complete copies of a sentient being raise interesting questions regarding identity and individuality.
Artificial Neural.docx (Size: 666.33 KB / Downloads: 26)
The human brain contains about 100 billion nerve cells called neurons, each individually linked to other neurons by way of connectors called axons and dendrites. Signals at the junctures (synapses) of these connections are transmitted by the release and detection of chemicals known as neurotransmitters. The established neuroscientific consensus is that the human mind is largely an emergent property of the information processing of this neural network.
Importantly, neuroscientists have stated that important functions performed by the mind, such as learning, memory, and consciousness, are due to purely physical and electrochemical processes in the brain and are governed by applicable laws. For example,Christof Koch and Giulio Tononi wrote in IEEE Spectrum:
"Consciousness is part of the natural world. It depends, we believe, only on mathematics and logic and on the imperfectly known laws of physics, chemistry, and biology; it does not arise from some magical or otherworldly quality."[5]
The concept of mind uploading is based on this mechanistic view of the mind, and denies thevitalist view of human life and consciousness.
Eminent computer scientists and neuroscientists have predicted that computers will be capable of thought and even attain consciousness, including Koch and Tononi,[5] Douglas Hofstadter,[6] Jeff Hawkins,[6] Marvin Minsky,[7] Randal A. Koene,[8] and Rodolfo Llinas.[9]
Such a machine intelligence capability might provide a computational substrate necessary for uploading.
However, even though uploading is dependent upon such a general capability it is conceptually distinct from general forms of AI in that it results from dynamic reanimation of information derived from a specific human mind so that the mind retains a sense of historical identity (other forms are possible but would compromise or eliminate the life-extension feature generally associated with uploading). The transferred and reanimated information would become a form of artificial intelligence, sometimes called an infomorph or "noömorph."
Many theorists have presented models of the brain and have established a range of estimates of the amount of computing power needed for partial and complete simulations.[citation needed] Using these models, some have estimated that uploading may become possible within decades if trends such as Moore's Law continue.[10]
Immortality/backup
In theory, if the information and processes of the mind can be disassociated from the biological body, they are no longer tied to the individual limits and lifespan of that body. Furthermore, information within a brain could be partly or wholly copied or transferred to one or more other substrates (including digital storage or another brain), thereby reducing or eliminating mortality risk. This general proposal appears to have been first made in the biomedical literature in 1971 by biogerontologist George M. Martin of the University of Washington.[3]
Speedup
A computer-based intelligence such as an upload could potentially think much faster than a human even if it were no more intelligent. Human neurons exchange electrochemical signals with a maximum speed of about 150 meters per second, whereas the speed of lightis about 300 million meters per second, about two million times faster. Also, neurons can generate a maximum of about 200 to 1000action potentials or "spikes" per second, whereas the number of signals per second in modern[when?] computer chips is about 3GHz[citation needed] (about two million times greater) and expected to increase by at least a factor 100. Therefore, even if the computer components responsible for simulating a brain were not significantly smaller than a biological brain, and even if the temperature of these components was not significantly lower, Eliezer Yudkowsky of the Singularity Institute for Artificial Intelligence calculates a theoretical upper bound for the speed of a future artificial neural network. It could in theory run about 1 million times faster than a real brain, experiencing about a year of subjective time in only 31 seconds of real time.[11][12][13]
However, such a massively parallel implementation would require separate computational units for each of the hundred billion neurons and each of the hundred trillion synapses. That requires an enormously large computer or artificial neural network in comparison with today's super-computers.[12] In a less futuristic implementation, time-sharing would allow several neurons to be emulated sequentially by the same computational unit. Thus the size of the computer would be restricted, but the speedup would be lower. Assuming thatcortical minicolumns organized into hypercolumns are the computational units, mammal brains can be emulated by today's super computers, but with slower speed than in a biological brain.[14]
Space travel
Mind uploading poses potential benefits for interstellar space travel because it would allow immortal beings to travel the cosmos without suffering from extreme acceleration. A whole society of uploads can be emulated by a computer on a very small spaceship, that would consume much less energy than traditional space travels. The uploads would have control of the ship and would be able to make decisions about the crafts voyage in real time, independent of signals from Earth, that might eventually take months or years to reach the craft as it journeys out into the cosmos. Because a virtual conscious can be set into a state of hibernation, or slowed down, the virtual minds need not experience the boredom of hundreds if not thousands of years of travel. Instead they would only awake when on board computers detected that the craft had arrived at its destination. In the book Omega point, the author suggests that the universe eventually would be colonized by such machine intelligence.
Another possibility for travel would be to transmit a mind via laser, or via radio between two already inhabited locations. Such travel would require only the energy to transmit enough powerful signals so that they reach the target destination. The travelers experienced time from transmitter to receiver would be instantaneous.
Multiple/parallel existence
Another concept explored in science fiction is the idea of more than one running "copy" of a human mind existing at once. Such copies could potentially allow an "individual" to experience many things at once, and later integrate the experiences of all copies into a central mentality at some point in the future, effectively allowing a single sentient being to "be many places at once" and "do many things at once"; this concept has been explored in fiction. Such partial and complete copies of a sentient being raise interesting questions regarding identity and individuality.